One day, when I have a bit more spare time, I'm going invent a medication which could be plausibly abbreviated NKDA, such as norketodopamine. (Does that name even make sense? Don't ask me, I'm a idiot blogger not a biochemist. But if you can have owlbears, I can have this.)
Then I will discover that it is not only therapeutically vital for the treatment of depression, acne, obesity, ischaemic heart disease, or some other such common condition, but also lethal if treatment is abruptly ceased.
And all over the world, pharmacists will have conniptions because patients will be bringing in prescriptions for norketodopamine re-supply, but the script will also have written, in the little box for Allergies/Adverse Reactions:
(Wait for it)
(You can see it coming, can't you?)
That will be briefly amusing for me as I lounge on my Throne Of Spleens, contemplating my empire and watching the dancing girls.